Every day in the world a lot of information is published and made available to the people through different information media, e.g. press, television, the Internet. The amount of information is rapidly increasing.
Unfortunately, the vast amount of information provided by the sources of information currently available can often be overwhelming to an individual, and that individual may become incapable of, or uninterested in, sorting through the information for items that he or she finds of interest. Therefore, what is needed is a service or ability to provide a user with only that information which the user will find of interest.
It has been common for a long time to filter content items on the basis of “keywords”. Keywords are provided by a user to a software application; the software application may be local to the user's computer or may be running on a remote computer connected to the user's computer through e.g. the Internet. The software application returns to the user all the available content items that are associated to the keywords specified by the user.
Keywords are a very common type of metadata. In the past, “metadata” was defined as “information about information”; as an example, the “title” and the “abstract” of an “article” is metadata as they provide information on the content of the article that is the information itself.
More sophisticated methods have been developed for the purpose of filtering content information. These methods are based on the use of metadata for indexing the various content items, particularly “authored metadata”, i.e. metadata associated to a content item by the author of the content item on by another person.
Effective filtering of content items often requires knowledge about the user, e.g. user habits and/or user preferences.
An interesting overview on filtering documents through the use of metadata and user profiles can by found in the article by Erika Savia et al., “Metadata Based Matching of Documents and User Profiles”, in Proc. 8th Finnish Artificial Intelligence Conference, Human and Artificial Information Processing, pages 61-69, 1998.
From international patent application WO 02/41579, it is known a method for grouping and transmitting multimedia data. Multimedia data are analysed in terms of their content, corresponding metadata are extracted by a metadata extraction module and a user profile is prepared. Prior to receiving multimedia data from a central unit, the user sets at least parts of the user data of the user profile, by means of a communication device, and/or modifies the same. Multimedia data are selected by means of the metadata and on the basis of the user profile, and content-oriented multimedia data optimised in a user-specific manner is produced from the selected multimedia data by means of a repackaging module. Said content-oriented multimedia data optimised in a user-specific manner is stored in a data base of a content module of the central unit and provided to the user.
According to this international patent application (page 8, lines 6-14), the metadata are retrieved on the basis of a content-based indexing technology such as one of those described e.g. in U.S. Pat. Nos. 5,210,868 and No. 5,414,644.